xref: /netbsd-src/sys/kern/tty_subr.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1993, 1994 Theo de Raadt
3  * All rights reserved.
4  *
5  * Per Lindqvist <pgd@compuram.bbt.se> supplied an almost fully working
6  * set of true clist functions that this is very loosely based on.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by Theo de Raadt.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  *	$Id: tty_subr.c,v 1.7 1994/05/25 10:00:26 deraadt Exp $
34  */
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/buf.h>
39 #include <sys/ioctl.h>
40 #include <sys/tty.h>
41 #include <sys/clist.h>
42 #include <sys/malloc.h>
43 
44 /*
45  * At compile time, choose:
46  * There are two ways the TTY_QUOTE bit can be stored. If QBITS is
47  * defined we allocate an array of bits -- 1/8th as much memory but
48  * setbit(), clrbit(), and isset() take more cpu. If QBITS is
49  * undefined, we just use an array of bytes.
50  *
51  * If TTY_QUOTE functionality isn't required by a line discipline,
52  * it can free c_cq and set it to NULL. This speeds things up,
53  * and also does not use any extra memory. This is useful for (say)
54  * a SLIP line discipline that wants a 32K ring buffer for data
55  * but doesn't need quoting.
56  */
57 #define QBITS
58 
59 #ifdef QBITS
60 #define QMEM(n)		((((n)-1)/NBBY)+1)
61 #else
62 #define QMEM(n)		(n)
63 #endif
64 
65 
66 /*
67  * Initialize clists.
68  */
69 void
70 cinit()
71 {
72 }
73 
74 /*
75  * Initialize a particular clist. Ok, they are really ring buffers,
76  * of the specified length, with/without quoting support.
77  */
78 int
79 clalloc(clp, size, quot)
80 	struct clist *clp;
81 	int size;
82 	int quot;
83 {
84 
85 	MALLOC(clp->c_cs, u_char *, size, M_TTYS, M_WAITOK);
86 	if (!clp->c_cs)
87 		return (-1);
88 	bzero(clp->c_cs, size);
89 
90 	if(quot) {
91 		MALLOC(clp->c_cq, u_char *, QMEM(size), M_TTYS, M_WAITOK);
92 		if (!clp->c_cq) {
93 			FREE(clp->c_cs, M_TTYS);
94 			return (-1);
95 		}
96 		bzero(clp->c_cs, QMEM(size));
97 	} else
98 		clp->c_cq = (u_char *)0;
99 
100 	clp->c_cf = clp->c_cl = (u_char *)0;
101 	clp->c_ce = clp->c_cs + size;
102 	clp->c_cn = size;
103 	clp->c_cc = 0;
104 	return (0);
105 }
106 
107 void
108 clfree(clp)
109 	struct clist *clp;
110 {
111 	if(clp->c_cs)
112 		FREE(clp->c_cs, M_TTYS);
113 	if(clp->c_cq)
114 		FREE(clp->c_cq, M_TTYS);
115 	clp->c_cs = clp->c_cq = (u_char *)0;
116 }
117 
118 
119 /*
120  * Get a character from a clist.
121  */
122 int
123 getc(clp)
124 	struct clist *clp;
125 {
126 	register int c = -1;
127 	int s;
128 
129 	s = spltty();
130 	if (clp->c_cc == 0)
131 		goto out;
132 
133 	c = *clp->c_cf & 0xff;
134 	if (clp->c_cq) {
135 #ifdef QBITS
136 		if (isset(clp->c_cq, clp->c_cf - clp->c_cs) )
137 			c |= TTY_QUOTE;
138 #else
139 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
140 			c |= TTY_QUOTE;
141 #endif
142 	}
143 	if (++clp->c_cf == clp->c_ce)
144 		clp->c_cf = clp->c_cs;
145 	if (--clp->c_cc == 0)
146 		clp->c_cf = clp->c_cl = (u_char *)0;
147 out:
148 	splx(s);
149 	return c;
150 }
151 
152 /*
153  * Copy clist to buffer.
154  * Return number of bytes moved.
155  */
156 int
157 q_to_b(clp, cp, count)
158 	struct clist *clp;
159 	u_char *cp;
160 	int count;
161 {
162 	register int cc;
163 	u_char *p = cp;
164 	int s;
165 
166 	s = spltty();
167 	/* optimize this while loop */
168 	while (count > 0 && clp->c_cc > 0) {
169 		cc = clp->c_cl - clp->c_cf;
170 		if (clp->c_cf >= clp->c_cl)
171 			cc = clp->c_ce - clp->c_cf;
172 		if (cc > count)
173 			cc = count;
174 		bcopy(clp->c_cf, p, cc);
175 		count -= cc;
176 		p += cc;
177 		clp->c_cc -= cc;
178 		clp->c_cf += cc;
179 		if (clp->c_cf == clp->c_ce)
180 			clp->c_cf = clp->c_cs;
181 	}
182 	if (clp->c_cc == 0)
183 		clp->c_cf = clp->c_cl = (u_char *)0;
184 	splx(s);
185 	return p - cp;
186 }
187 
188 /*
189  * Return count of contiguous characters in clist.
190  * Stop counting if flag&character is non-null.
191  */
192 ndqb(clp, flag)
193 	struct clist *clp;
194 	int flag;
195 {
196 	int count = 0;
197 	register int i;
198 	register int cc;
199 	int s;
200 
201 	s = spltty();
202 	if ((cc = clp->c_cc) == 0)
203 		goto out;
204 
205 	if (flag == 0) {
206 		count = clp->c_cl - clp->c_cf;
207 		if (count < 0)
208 			count = clp->c_ce - clp->c_cf;
209 		goto out;
210 	}
211 
212 	i = clp->c_cf - clp->c_cs;
213 	if(flag & TTY_QUOTE) {
214 		while (cc-- > 0 && (clp->c_cs[i++] & (flag & ~TTY_QUOTE)) &&
215 		    !isset(clp->c_cq, i)) {
216 			count++;
217 			if (i == clp->c_cn)
218 				break;
219 		}
220 	} else {
221 		while (cc-- > 0 && (clp->c_cs[i++] & flag)) {
222 			count++;
223 			if (i == clp->c_cn)
224 				break;
225 		}
226 	}
227 out:
228 	splx(s);
229 	return count;
230 }
231 
232 /*
233  * Flush count bytes from clist.
234  */
235 void
236 ndflush(clp, count)
237 	struct clist *clp;
238 	int count;
239 {
240 	register int cc;
241 	int s;
242 
243 	s = spltty();
244 	if (count == clp->c_cc) {
245 		clp->c_cc = 0;
246 		clp->c_cf = clp->c_cl = (u_char *)0;
247 		goto out;
248 	}
249 	/* optimize this while loop */
250 	while (count > 0 && clp->c_cc > 0) {
251 		cc = clp->c_cl - clp->c_cf;
252 		if (clp->c_cf >= clp->c_cl)
253 			cc = clp->c_ce - clp->c_cf;
254 		if (cc > count)
255 			cc = count;
256 		count -= cc;
257 		clp->c_cc -= cc;
258 		clp->c_cf += cc;
259 		if (clp->c_cf == clp->c_ce)
260 			clp->c_cf = clp->c_cs;
261 	}
262 	if (clp->c_cc == 0)
263 		clp->c_cf = clp->c_cl = (u_char *)0;
264 out:
265 	splx(s);
266 }
267 
268 /*
269  * Put a character into the output queue.
270  */
271 int
272 putc(c, clp)
273 	int c;
274 	struct clist *clp;
275 {
276 	register u_char *q;
277 	register int i;
278 	int r = -1;
279 	int s;
280 
281 	s = spltty();
282 	if (clp->c_cc == clp->c_cn)
283 		goto out;
284 
285 	if (clp->c_cc == 0) {
286 		if (!clp->c_cs) {
287 #if defined(DIAGNOSTIC) || 1
288 			printf("putc: required clalloc\n");
289 #endif
290 			if(clalloc(clp, 1024, 1)) {
291 out:
292 				splx(s);
293 				return -1;
294 			}
295 		}
296 		clp->c_cf = clp->c_cl = clp->c_cs;
297 	}
298 
299 	*clp->c_cl = c & 0xff;
300 	i = clp->c_cl - clp->c_cs;
301 	if (clp->c_cq) {
302 #ifdef QBITS
303 		if (c & TTY_QUOTE)
304 			setbit(clp->c_cq, i);
305 		else
306 			clrbit(clp->c_cq, i);
307 #else
308 		q = clp->c_cq + i;
309 		*q = (c & TTY_QUOTE) ? 1 : 0;
310 #endif
311 	}
312 	clp->c_cc++;
313 	clp->c_cl++;
314 	if (clp->c_cl == clp->c_ce)
315 		clp->c_cl = clp->c_cs;
316 	splx(s);
317 	return 0;
318 }
319 
320 #ifdef QBITS
321 /*
322  * optimized version of
323  *
324  * for (i = 0; i < len; i++)
325  *	clrbit(cp, off + len);
326  */
327 void
328 clrbits(cp, off, len)
329 	u_char *cp;
330 	int off;
331 	int len;
332 {
333 	int sby, sbi, eby, ebi;
334 	register int i;
335 	u_char mask;
336 
337 	if(len==1) {
338 		clrbit(cp, off);
339 		return;
340 	}
341 
342 	sby = off / NBBY;
343 	sbi = off % NBBY;
344 	eby = (off+len) / NBBY;
345 	ebi = (off+len) % NBBY;
346 	if (sby == eby) {
347 		mask = ((1 << (ebi - sbi)) - 1) << sbi;
348 		cp[sby] &= ~mask;
349 	} else {
350 		mask = (1<<sbi) - 1;
351 		cp[sby++] &= mask;
352 
353 		mask = (1<<ebi) - 1;
354 		cp[eby] &= ~mask;
355 
356 		for (i = sby; i < eby; i++)
357 			cp[i] = 0x00;
358 	}
359 }
360 #endif
361 
362 /*
363  * Copy buffer to clist.
364  * Return number of bytes not transfered.
365  */
366 int
367 b_to_q(cp, count, clp)
368 	u_char *cp;
369 	int count;
370 	struct clist *clp;
371 {
372 	register int i, cc;
373 	register u_char *p = cp;
374 	int off, s;
375 
376 	if (count <= 0)
377 		return 0;
378 
379 	s = spltty();
380 	if (clp->c_cc == clp->c_cn)
381 		goto out;
382 
383 	if (clp->c_cc == 0) {
384 		if (!clp->c_cs) {
385 #if defined(DIAGNOSTIC) || 1
386 			printf("b_to_q: required clalloc\n");
387 #endif
388 			if(clalloc(clp, 1024, 1))
389 				goto out;
390 		}
391 		clp->c_cf = clp->c_cl = clp->c_cs;
392 	}
393 
394 	/* optimize this while loop */
395 	while (count > 0 && clp->c_cc < clp->c_cn) {
396 		cc = clp->c_ce - clp->c_cl;
397 		if (clp->c_cf > clp->c_cl)
398 			cc = clp->c_cf - clp->c_cl;
399 		if (cc > count)
400 			cc = count;
401 		bcopy(p, clp->c_cl, cc);
402 		if (clp->c_cq) {
403 #ifdef QBITS
404 			clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc);
405 #else
406 			bzero(clp->c_cl - clp->c_cs + clp->c_cq, cc);
407 #endif
408 		}
409 		p += cc;
410 		count -= cc;
411 		clp->c_cc += cc;
412 		clp->c_cl += cc;
413 		if (clp->c_cl == clp->c_ce)
414 			clp->c_cl = clp->c_cs;
415 	}
416 out:
417 	splx(s);
418 	return count;
419 }
420 
421 static int cc;
422 
423 /*
424  * Given a non-NULL pointer into the clist return the pointer
425  * to the next character in the list or return NULL if no more chars.
426  *
427  * Callers must not allow getc's to happen between firstc's and getc's
428  * so that the pointer becomes invalid.  Note that interrupts are NOT
429  * masked.
430  */
431 u_char *
432 nextc(clp, cp, c)
433 	struct clist *clp;
434 	register u_char *cp;
435 	int *c;
436 {
437 
438 	if (clp->c_cf == cp) {
439 		/*
440 		 * First time initialization.
441 		 */
442 		cc = clp->c_cc;
443 	}
444 	if (cc == 0 || cp == NULL)
445 		return NULL;
446 	if (--cc == 0)
447 		return NULL;
448 	if (++cp == clp->c_ce)
449 		cp = clp->c_cs;
450 	*c = *cp & 0xff;
451 	if (clp->c_cq) {
452 #ifdef QBITS
453 		if (isset(clp->c_cq, cp - clp->c_cs))
454 			*c |= TTY_QUOTE;
455 #else
456 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
457 			*c |= TTY_QUOTE;
458 #endif
459 	}
460 	return cp;
461 }
462 
463 /*
464  * Given a non-NULL pointer into the clist return the pointer
465  * to the first character in the list or return NULL if no more chars.
466  *
467  * Callers must not allow getc's to happen between firstc's and getc's
468  * so that the pointer becomes invalid.  Note that interrupts are NOT
469  * masked.
470  *
471  * *c is set to the NEXT character
472  */
473 u_char *
474 firstc(clp, c)
475 	struct clist *clp;
476 	int *c;
477 {
478 	int empty = 0;
479 	register u_char *cp;
480 	register int i;
481 
482 	cc = clp->c_cc;
483 	if (cc == 0)
484 		return NULL;
485 	cp = clp->c_cf;
486 	*c = *cp & 0xff;
487 	if(clp->c_cq) {
488 #ifdef QBITS
489 		if (isset(clp->c_cq, cp - clp->c_cs))
490 			*c |= TTY_QUOTE;
491 #else
492 		if (*(cp - clp->c_cs + clp->c_cq))
493 			*c |= TTY_QUOTE;
494 #endif
495 	}
496 	return clp->c_cf;
497 }
498 
499 /*
500  * Remove the last character in the clist and return it.
501  */
502 int
503 unputc(clp)
504 	struct clist *clp;
505 {
506 	unsigned int c = -1;
507 	int s;
508 
509 	s = spltty();
510 	if (clp->c_cc == 0)
511 		goto out;
512 
513 	if (clp->c_cl == clp->c_cs)
514 		clp->c_cl = clp->c_ce - 1;
515 	else
516 		--clp->c_cl;
517 	clp->c_cc--;
518 
519 	c = *clp->c_cl & 0xff;
520 	if (clp->c_cq) {
521 #ifdef QBITS
522 		if (isset(clp->c_cq, clp->c_cl - clp->c_cs))
523 			c |= TTY_QUOTE;
524 #else
525 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
526 			c |= TTY_QUOTE;
527 #endif
528 	}
529 	if (clp->c_cc == 0)
530 		clp->c_cf = clp->c_cl = (u_char *)0;
531 out:
532 	splx(s);
533 	return c;
534 }
535 
536 /*
537  * Put the chars in the from queue on the end of the to queue.
538  */
539 void
540 catq(from, to)
541 	struct clist *from, *to;
542 {
543 	int c;
544 
545 	while ((c = getc(from)) != -1)
546 		putc(c, to);
547 }
548